[SCSI] zfcp: Track fabric and channel latencies provided by FCP adapter

Add the infrastructure to retrieve the fabric and channel latencies
from FSF commands for each SCSI command that has been processed. For
each unit, the sum, min, max and number of requests is tracked.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index bda8c77b22da..306fcd0cae31 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -708,6 +708,24 @@ struct zfcp_erp_action {
         struct timer_list timer;
 };
 
+struct fsf_latency_record {
+        u32 min;
+        u32 max;
+        u64 sum;
+};
+
+struct latency_cont {
+        struct fsf_latency_record channel;
+        struct fsf_latency_record fabric;
+        u64 counter;
+};
+
+struct zfcp_latencies {
+        struct latency_cont read;
+        struct latency_cont write;
+        struct latency_cont cmd;
+        spinlock_t lock;
+};
 
 struct zfcp_adapter {
         struct list_head        list;              /* list of adapters */
@@ -723,6 +741,7 @@ struct zfcp_adapter {
         u32                     adapter_features;  /* FCP channel features */
         u32                     connection_features; /* host connection features */
         u32                     hardware_version;  /* of FCP channel */
+        u16                     timer_ticks;       /* time int for a tick */
         struct Scsi_Host        *scsi_host;        /* Pointer to mid-layer */
         struct list_head        port_list_head;    /* remote port list */
         struct list_head        port_remove_lh;    /* head of ports to be
@@ -822,6 +841,7 @@ struct zfcp_unit {
         struct scsi_device     *device;        /* scsi device struct pointer */
         struct zfcp_erp_action erp_action;     /* pending error recovery */
         atomic_t               erp_counter;
+        struct zfcp_latencies   latencies;
 };
 
 /* FSF request */